Recently, spectrum around 60 GHz has attracted, e.g., industrial companies and research to explore its potential in wireless communications, short-distance data transfer, and other applications. Phased arrays of antennas may be used to increase antenna gain. A separate phase control may be used to steer the pattern of the antenna to obtain maximum gain.
With the use of planar printed circuit board (PCB) technology, or any other planar, multi-layer substrate technology, antennas are limited in their ability to steer the pattern of the antenna in certain dimensions or in certain directions. For example, using a patch array implemented on a PCB, the radiation pattern emerging from the patch array will be substantially perpendicular to the plane of the PCB. Using an end-fire array, the emerging radiation pattern will be substantially parallel to the plane of the PCB (e.g., the emerging radiation pattern will “fire off the edge” of the PCB).